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| Titel |
Ultraviolet anomalies of the WASP-12 and HD 189733 systems: Trojan satellites as a plasma source |
| VerfasserIn |
Kristina Kislyakova, Elke Pilat-Lohinger, Barbara Funk, Helmut Lammer, Luca Fossati, Siegfried Eggl, Richard Schawarz, Mohammed Boudyada, Nikolai Erkaev |
| Konferenz |
EGU General Assembly 2017
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| Medientyp |
Artikel
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| Sprache |
en
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| Digitales Dokument |
PDF |
| Erschienen |
In: GRA - Volume 19 (2017) |
| Datensatznummer |
250140224
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| Publikation (Nr.) |
 EGU/EGU2017-3582.pdf |
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| Zusammenfassung |
| We suggest an additional possible plasma source in the WASP-12 and HD189733b systems to
explain part of the phenomena observed in ultraviolet (UV) light curves during
planetary transits. In the proposed scenario, material originates from the molten surface
of Trojan satellites on orbits near the Lagrange points L4 and L5. We show that
the temperature at the orbital location of WASP-12b is high enough to melt the
surface of rocky Trojans and to form shallow lava oceans on them. At the orbital
distance of WASP-12b, this leads to the release of elements such as Mg and Ca, which
are expected to surround the system. The predicted Mg and Ca outgassing rates
from two Io-sized WASP-12b Trojans are ≈ 2.2 × 1027 s−1 and ≈ 2.2 × 1026 s−1,
respectively. Trojan outgassing can lead to the observed lack of emission in MgII h&k and
CaII H&K line cores of WASP-12. For HD 189733b, the mechanism is only marginally
possible due to the lower temperature. The early ingress of HD 189733b observed in
the far-UV (FUV) CII doublet couldn’t be explained by this mechanism due to
absence of carbon within elements outgassed by molten lava. We investigate the
long-term stability region of WASP-12b and HD 189733b in case of planar and
inclined motion of these satellites and show that unlike the classical exomoons
orbiting the planet, Io-sized Trojans can be stable for the whole systems life time. |
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